Michael Kearney (1888). "Biographical Preface". Rubáiyát of Omar Khayyám in English verse. By Omar Khayyam. Translated by Edward FitzGerald. New York and Boston: Houghton, Mifflin. p. 17.
Francois De Blois, Persian Literature – A Bio-Bibliographical Survey: Poetry of the Pre-Mongol Period (2004), p. 307.
Preface to a facsimile of the first edition (no year [c. 1900], "from the fine copy owned by Charles Dana Burrage" [1857–1926]).
Francois De Blois, Persian Literature – A Bio-Bibliographical Survey: Poetry of the Pre-Mongol Period (2004), p. 312.
Dashti, Ali (25 February 2011) [1971]. In Search of Omar Khayyam. Routledge Library Editions: Iran. Vol. 12. Translated by Elwood-Sutton, L. P. Routledge. pp. 18–19. ISBN978-0-415-60851-0.
"Every line of the Rubaiyat has more meaning than almost anything you could read in Sufi literature". Abdullah Dougan, Who is the Potter?, Gnostic Press 1991 ISBN0-473-01064-X
"Rubaije Omera Hajjama". mullasadra.com. Archived from the original on 6 October 2010. Retrieved 9 March 2021.{{cite web}}: CS1 maint: unfit URL (link)